Harmonic phase transition in solids under high pressures

Abstract

The binding energy of atoms in substances exceeds the energy of the harmonic vibrator owing to the anharmonicity (Fig. 1). Experiments show reduction of the anharmonic component of binding energy in solids under high pressures. These data allow us to determine values of pressures when the coefficients of thermal expansions become equal to zero, i.e. when the harmonic phase transition occurs.